Research Objectives: The long term goal of this investigation is to study the role of manganese in lysosomal function in an attempt to establish the mechanism for the decreased content of mucopolysaccharides in cartilage from Manganese deficient chicks. The initial studies will compare the activities of the lysosomal hydrolases to the UDP-Glycosyl Transferases involved in mucopolysaccharide degradation and biosynthesis using cartilage from manganese deficient and control chicks as an experimental model. The extracellular enzyme, lysozyme, will also be measured in these cartilage preparations. Mucopolysaccharide turnover will be measured in cartilage from control and deficient chicks using 35 SO4 and C14-compounds for in vivo labeling. These data will allow more accurate interpretation of the enzyme activities obtained above and delineation of the abnormality in metabolic control created by manganese deficiency. An attempt will be made to correct this abnormality both in vitro and in vivo using manganese salts.